Combination of inactivated tumor cells and GM-CSF effective against neuroblastomas.

2002 DEC 18 - (NewsRx.com & NewsRx.net) -- by Maria G. Essig, MS, ELS, senior medical writer - Treatment with irradiated tumor cells plus an infusion of granulocyte-macrophage colony-stimulating factor inhibited the growth of neuroblastoma tumors in mice, according to a report in the the Journal of Pediatric Surgery.

Yun Chen and colleagues at National Taiwan University Hospital in Taipei determined survival in A/J mice with wild-type neuro-2a neuroblastoma tumors that were treated with five doses of an irradiated tumor cell vaccine, continuous infusion of 1 ng/day or 10 ng/day granulocyte-macrophage colony-stimulating factor (GM-CSF), or the vaccine followed by GM-CSF infusion. A group of untreated mice acted as controls.

The investigators found a significant reduction in tumor growth and increase in survival time in mice treated with the vaccine and the higher GM-CSF dose in comparison to the controls (p

Treatment with the vaccine alone or with the vaccine plus the low-dose GM-CSF infusion was significantly less effective (p

Tumor regression and long-term survival were achieved in one mouse that received the vaccine plus high-dose GM-CSF. This mouse was also protected against a subcutaneous rechallenge with wild-type neuro-2a neuroblastoma cells.

Infiltration of CD4+ and CD8+ T lymphocytes was significant in the tumors of mice treated with the irradiated tumor cell vaccine and higher-dose GM-CSF infusion.

"The results suggest that an irradiated tumor vaccine combined with continuous localized infusion of GM-CSF may induce a tumor-specific antitumor immune ...